Compositions and their uses

ABSTRACT

Aqueous compositions, methods of manufacturing such aqueous compositions, and methods of removing reducing and/or suppressing malodours using such aqueous compositions are described. These compositions utilize a combination of hydrogen peroxide, a source of copper II, nonionic surfactant and alcohol to provide a highly effective and stable malodour removing, reducing and/or suppressing composition. The compositions are particularly useful as aerosol compositions for effective malodour removal, reduction and/or suppression in particular malodours from open sites such as landfill and in closed domestic environments such as the home. Also described is a stabilized hydrogen peroxide solution, which is stable on the addition of copper (II) salts.

FIELD OF INVENTION

The present invention is concerned with aqueous compositions, methods ofmanufacturing such aqueous compositions and methods of removing and/orsuppressing malodours using aqueous compositions.

BACKGROUND ART

Odours or malodours may be generated by many industrial processes andactivities as well as occurring through other forms of human activitysuch as waste disposal into landfill as well as from natural sources.

A number of compositions, methods and processes have been developed inthe art to deal with the problem of malodour generation. The source ofthe malodour is typically one or more of the following chemicals orclass of chemicals; evil-smelling and toxic organic sulfur compounds,such as methylmercaptan, dimethyl sulfide and dimethyl disulphide,diallyl sulfide, ammonia, hydrogen sulfide, skatole (3-methyl indole)and the like. With these prior art solutions one strategy has been totreat and/or remove the chemical source of the malodour for example in awaste stream before release into the atmosphere. These strategiesrequire the treatment of process waste streams, both liquid and gaseousbefore release into the atmosphere. Examples of such malodour controlsystems are: mist filtration, thermal oxidation/incineration,biofiltration, adsorption, wet scrubbing/absorption, chemical treatmentand irradiation.

Despite the availability of various treatment strategies for industrialprocess waste streams malodour generation from such processes and theirrelated waste continues to be a problem. In addition these solutionsdirected to industrial waste streams are not applicable to malodourcontrol problems outside of the industrial plant in the openenvironment, where the malodour is from large area sources of varied andcomplex composition such as the malodours associated with landfill andother waste disposal sites. In addition these solutions directed toindustrial waste streams are not applicable to malodour control problemsassociated in closed domestic environments where the sources of malodourcan again be many and varied and in some instances difficult todetermine.

With reference to the problem of malodours in the open environment, onesolution is currently provided by Probe Industries and marketed underthe trade name AiroNaut™. This solution utilizes spraying techniqueswhere active compositions are deployed as ultra-fine droplets usuallyalong the boundary lines of the area source to suppress malodours. Thesprayer is a rotary atomizer, which uses centrifugal action to producebillions of droplets of aqueous composition in the form of a mist orfog.

With reference to the problem of malodours in the domestic environmentthere are many approaches to solving this problem. A wide variety ofdeodourizing compositions are known in the art, the most common of whichcontain perfumes to mask malodour. Odour masking is the intentionalconcealment of one odour by the addition of another. However preferenceto perfume is greatly varied and high levels are needed to ensure thatthe malodour is no longer noticeable. In addition masking does notactually remove the odourous compound or the source of the odour.

Odour modification, in which the odour is changed by, for example,chemical modification, has also been used. Current malodour modificationmethods known in the art are oxidative degradation, which uses oxidizingagents such as oxygen bleaches, chlorine, chlorinated materials such assodium hypochlorite, chlorine dioxide and potassium permanganate toreduce malodour, and reductive degradation which uses reducing agentssuch as sodium bisulfite to reduce malodour.

Other methods of odour control utilize actives that are targeted toreact with malodours having specific chemical functional groups.Examples of such actives are; biguanide polymers, which complex withorganic compounds containing organically bound N and/or S atoms andfatty alcohol esters of methyl methacrylic acid which react with thiols,amines, and aldehydes. Such actives are limited in the scope ofprotection which they afford because they only react with limited typesof malodour.

Other types of deodourizing compositions known in the art containantibacterial and antifungal agents which regulate themalodour-producing microorganisms found on the surface to which thedeodourizing composition is directed. Many skin deodorant products usethis technology. These compositions are not effective on malodours thathave already been produced and malodours that do not come from bacterialsources, such as tobacco, food odours or odours from open sources.

There is therefore a continuing need for alternative and/or moreeffective compositions and methods for open area source malodour controland for malodour control in the domestic environment.

DISCLOSURE OF THE INVENTION

The present invention relates to aqueous compositions that are suitablefor removing, reducing and/or suppressing odours and malodours, toarticles of manufacture comprising such compositions, methods of use ofsuch compositions and methods of manufacture of such compositionsincluding intermediate compositions for their manufacture. Thesecompositions are based on the combination of copper (II) and hydrogenperoxide in relatively stable compositions. Under normal conditions offormulation the combination of soluble copper and hydrogen peroxide inan aqueous environment would be inherently unstable with the copperspecies catalyzing the decomposition of the hydrogen peroxide. Thepresent invention through careful formulation and manufacturingprocedures results in a relatively stable combination of soluble copperand hydrogen peroxide in a combined aqueous solution. In thecompositions of the present invention the rate of decomposition, asevidenced by oxygen off gassing compared to a conventional mixture ofthese components is significantly reduced with compositions remainingactive for long periods of time after formulation. The compositions arefound to retain at least 75% of the active hydrogen peroxide componentafter one week of storage.

The odour-absorbing/suppressing compositions are designed to remove,reduce and/or suppress odours caused by a broad spectrum of organicodoriferous materials.

Thus in accordance with the present invention there is provided anaqueous composition comprising:

a) at least one source of copper,b) hydrogen peroxide or a source of hydrogen peroxide,c) one or more alcohols, andd) one or more surfactants.

This composition may be used as prepared in the form of a concentrate orit may be diluted with water prior to use. In one embodiment thecomposition is a malodour removing reducing or suppressing composition,preferably in the form of an aerosol.

The present invention further provides for a method for the manufactureof a composition concentrate according to the present invention, whichmethod comprises:

a) preparing an aqueous solution comprising at least one alcohol, atleast one surfactant and hydrogen peroxide, andb) adding a source of copper (II) to the solution prepared in (a).

It has been found that the solution of step (a) is a particularly stablehydrogen peroxide solution. Thus the present invention further providesfor a stabilized aqueous hydrogen peroxide solution comprising:

(i) hydrogen peroxide or a source of hydrogen peroxide,(ii) one or more alcohols, and(iii) one or more surfactants.

In a preferred method for the manufacture in step (a) the alcohol isadded to the surfactant before addition of water with mixing. In apreferred embodiment the hydrogen peroxide is added to thealcohol/surfactant mixture before the addition of water with carefulstirring. Water is preferably added to the mixture of alcohol,surfactant and hydrogen peroxide with mixing.

The source of copper is preferably copper (II), which may be added as asolid salt or other source of copper (II) to the mixture of step (a) inthe method for the manufacture. The copper (II) source may be introducedand preferably is introduced as an aqueous copper (II) solution. Thesource of copper is typically a copper salt and preferably a copper (II)salt. Inorganic copper (II) salts suitable for use in the presentinvention include copper bromide, copper carbonate, copper nitrate,copper chloride and copper sulphate, with hydrated copper sulphate beingthe most preferred. Simple organic copper salts suitable for use in thepresent invention include, copper lactate, copper formate, copperoxalate, copper acetate, and copper citrate. The preferred solublesource of copper is one or more organic copper salts and most preferablyis copper citrate. In some formulations a mixture of one or moreinorganic and one or more organic copper (II) salts may be used; in thissituation the preferred mixture is a copper sulphate/copper citratemixture.

When used the aqueous copper (II) solution is added to the solutionprepared under step (a) of the method with stirring. The preparation ofall solutions is preferably undertaken under ambient conditions oftemperature and pressure with no requirement for temperature control. Anideal mixing unit comprises an SS propeller/stirrer powered by anelectric motor in covered stainless steel tanks. When a solid source ofcopper (II) is used i.e. a salt then this may be added in a number ofapproximately equal proportions with stirring. It has been found that insome instances that organic copper (II) compounds such as copper citratefor example are difficult to dissolve in the mixture of step (a) oraqueous media prepared before addition to the mixture of step (a). Inthese situations it has been found that dissolution and formation of theactive component on addition of the copper (II) source to the mixture ofstep (a) is greatly improved if an approximately equimolar amount of thesodium or potassium salt of the acid is added in addition to the coppersalt. As an example when copper citrate is used an equimolar amount ofsodium citrate addition aids dissolution and formation of the activecomposition. It is preferred that when the copper source is such anorganic acid salt that this is used in combination with a comparable orcompatible sodium or potassium salt of the organic acid. It is envisagedthat the sodium salt may not be of the same organic acid.

When the aqueous copper solution is mixed with the solution preparedunder step (a) at temperatures in excess of 5° C., a brown precipitatemay be formed. It is believed that this is a precipitate of a copper(II) peroxy complex. This precipitate may often be observed when coppersulphate is used as the copper source. In a preferred embodiment whensuch a precipitate is formed a suitable buffering organic acid may beadded to the mixture. A preferred organic acid is citric acid, which maybe added to the mixture to aid dissolution of the precipitate andformation of the active composition. The suitable buffering organic acidmay be added to the mixture within the range 0.05 to 1 wt %, preferably0.1 to 0.75 wt %, more preferably 0.1 to 0.5 wt % and most preferably0.15 to 0.35 wt % of the composition.

On completion of the method for the manufacture the resulting bluesolution is a concentrated solution containing at least 1% by weight ofhydrogen peroxide. The concentrated solution is stable with little or nochange in colour even after several months of storage. This concentratemay now be used to manufacture malodour removing or suppressingcompositions according to the present invention by simple dilution withwater to the required concentration of copper and/or hydrogen peroxide.For some applications the composition may be used neat without dilution,especially with difficult to treat odorous situations.

Suitable surfactants are nonionic surfactants, anionic surfactants,cationic surfactants, amphoteric surfactants, zwitterionic surfactants,and mixtures thereof. However, it is most preferred that the surfactantcomprises one or more nonionic surfactants. When a surfactant containingone, or more, aliphatic alkyl group is used, it is preferred that itcontain relatively short alkyl chains of from about 5 to about 22 carbonatoms. When used preferred anionic surfactants are dialkylsulfosuccinate, alkylarylsulfonate, fatty alcohol sulfate, paraffinsulfonate, alkyl sarcosinate, alkyl isethionate salts having suitablecations, e.g., sodium, potassium, alkanol ammonium, etc., and mixturesthereof. Preferred amphoteric surfactants are the betaines. It ispreferred that the surfactant have good wetting properties. Alsopreferred are surfactants that have the hydrophilic groups situatedbetween hydrophobic chains, such as Pluronic RX surfactants, Surfynolsurfactants, polyethylene glycol diesters of fatty acids, fatty acidesters of ethoxylated sorbitans. dialkyl sulfosuccinate, di(C8-C12alkyl)di(C1-C2 alkyl)ammonium halides. and mixtures thereof; orsurfactants that have the hydrophobic chains situated betweenhydrophilic groups, such as Pluronic surfactants; and mixtures thereof.Mixtures of these surfactants and other types of surfactants are alsopreferred to form no-foaming or low-foaming solubilizing agents.

It is preferred that the surfactant is a non-ionic surfactant. Examplesof suitable non-ionic surfactants include those based on: alkylpoly(ethylene oxide); alkylphenol poly(ethylene oxide); copolymers ofpoly(ethylene oxide) and poly(propylene oxide) (commercially calledPoloxamers or Poloxamines); alkyl polyglucosides, including for exampleoctyl glucoside, decyl maltoside; fatty alcohols such as for examplecetyl alcohol and oleyl alcohol, cocamide MEA, cocamide DEA;polysorbates such as Tween 20 and Tween 80; dodecyl dimethylamine oxidesand alcohol ethoxylates. The preferred non-ionic surfactants are alcoholethoxylates of the following general structure (I):

R—(OCH₂CH₂)_(n)—OH   (I)

Wherein R is an alkyl group of the parent alcohol and n=number ofmolecules of ethylene oxide present. Preferably R is a hydrocarbon grouphaving from 5 to 22 carbon atoms (C₈ to C₂₂ alkyl group) and may be abranched or linear alkyl group. The surfactant may comprise a mixture ofcompounds of general structure (I) having one or more differenthydrocarbon groups. Preferably the surfactant has a hydrocarbon group Rhaving from 8 to 22 carbon atoms, more preferably having from 8 to 15carbon atoms and more preferably 9 to 11 carbon atoms. Preferably n isfrom 3 to 40, more preferably from 3 to 30, more preferably from 3 to20, more preferably from 5 to 10 and most preferably from 5 to 9. Onepreferred surfactant has an n value of 6.5. Preferred nonionicsurfactants are polyethylene glycol-polypropylene glycol blockcopolymers, such as PluronicX and Pluronic RX surfactants from BASF;TetronicX and Tetronic RX surfactants from BASF, ethoxylated branchedaliphatic diols such as SurfynolX surfactants from Air Products;ethoxylated alkyl phenols, such as IgepaIX surfactants fromRhone-Poulenc; ethoxylated aliphatic alcohols and carboxylic acids;polyethylene glycol diesters of fatty acids; fatty acid esters ofethoxylated sorbitans; and mixtures thereof. The most preferredsurfactants are nonionic ethoxylated 8 to 15 carbon atom aliphaticalcohols with from 5 to 10 ethoxyl units.

The alcohol may be a simple aliphatic alcohol, diol or polyol. The mostpreferred alcohols are diols. The preferred diols are low molecularweight diols having from 3 to 10 carbon atoms in the alkyl moiety. Themost preferred diols are vicinal diols such as for examplepropane-1,2-diol (monopropylene glycol), which is the most preferreddiol.

The hydrogen peroxide preferably used as an aqueous composition havingfrom 10 to 50% by weight of hydrogen peroxide in water. The hydrogenperoxide composition is preferably from 20 to 40% by weight hydrogenperoxide, more preferably from 25 to 40% and most preferably from 30 to40% by weight hydrogen peroxide. A suitable composition is approximately35% by weight hydrogen peroxide.

The composition concentrate according to the present invention maycomprise from 1 to 20%, more preferably 1 to 10%, more preferably 2 to10% and most preferably 3 to 6% by weight of hydrogen peroxide presentas a complex with copper (II). In some applications the undilutedconcentrate may be used for malodour suppression. However, it ispreferred that the concentrate is diluted and that the concentration ofhydrogen peroxide in the final composition is 5% or less by weight. Thusthe concentrate may be diluted to provide a malodour removing orsuppressing composition according to the present invention. Typicallycompositions with up to 3% by weight hydrogen peroxide, more preferablyup to 2% by weight of hydrogen peroxide and most preferably up to 1.75%by weight hydrogen peroxide may be used for the suppression and/orremoval, reduction of strong malodour from compost leachates, land-fillsites, lagoon treatment, sewage storage tanks etc and at thisconcentration the composition is typically not deployed in the form ofan aerosol but is deployed by liquid injection, drip feed or liquidspraying techniques. In a preferred embodiment the composition is at adilution providing 1% or less by weight of hydrogen peroxide, preferably0.5% or less by weight of hydrogen peroxide, more preferably 0.1% orless by weight and most preferably 0.055% by weight or less of hydrogenperoxide. At these low levels of hydrogen peroxide the composition isideally suited for application as an aerosol through a rotary atomizersystems similar to that used for the deployment of AiroNaut™compositions, although stronger solutions may be used. These solutionsmay also be dispensed through a propellant driven aerosol or mechanicalaerosol container suitable for domestic use. At a concentration of 0.15%the aerosol contains 1500 ppm of hydrogen peroxide. At a concentrationof 0.0525% by weight hydrogen peroxide the aerosol contains 525 ppm ofhydrogen peroxide. It is preferred that the aerosol compositions of thepresent invention have 2000 ppm or less of hydrogen peroxide, preferably1500 ppm or less of hydrogen peroxide, more preferably 550 ppm or lessof hydrogen peroxide, more preferably 200 ppm or less and mostpreferably 150 ppm or less of hydrogen peroxide.

In the compositions of the present invention it is preferred that thealcohol is present at a concentration of 20% or less by weight based onthe total weight of the composition, preferably 15% or less by weight,more preferably 12% or less by weight and most preferably 10% or less byweight.

In the compositions of the present invention it is preferred that thesurfactant is present at a concentration from 1 to 55% by weight basedon the total weight of the composition. Preferably, it is present at aconcentration from 2 to 45% by weight, more preferably 2 to 30% byweight, more preferably 2 to 20% by weight, more preferably 2 to 15% byweight and most preferably 2 to 12% by weight. One preferred compositioncomprises 3 to 12% by weight of surfactant.

In the compositions of the present invention the amount of copper (II)present is dependant on the level of hydrogen peroxide in thecomposition. Preferably the amount of copper (II) present in thecomposition is selected to provide a mole ratio of copper (II) tohydrogen peroxide within the range of 1:50 to 1:200 and more preferablywithin the range of 1:75 to 1:150. One preferred composition comprises amole ratio of copper (II) to hydrogen peroxide of 1:100. In thecompositions of the present invention the balance of the composition inorder to achieve a 100% by weight composition is water.

In a further aspect the composition may further comprise one or morecyclodextrins. As used herein, the term “cyclodextrin” includes any ofthe known cyclodextrins such as unsubstituted cyclodextrins containingfrom six to twelve glucose units, especially, alpha-cyclodextrin,beta-cyclodextrin, gamma-cyclodextrin and/or their derivatives and/ormixtures thereof. The alpha-cyclodextrin consists of six glucose units,the beta-cyclodextrin consists of seven glucose units, and thegamma-cyclodextrin consists of eight glucose units arranged indonut-shaped rings. The specific coupling and conformation of theglucose units give the cyclodextrins a rigid, conical molecularstructures with hollow interiors of specific volumes. The “lining” ofeach internal cavity is formed by hydrogen atoms and glycosidic bridgingoxygen atoms; therefore, this surface is fairly hydrophobic.

The cavities within the cyclodextrin in the solution of the presentinvention should remain essentially unfilled (the cyclodextrin remainsuncomplexed) while in solution, in order to allow the cyclodextrin toabsorb various odour molecules when the solution is applied to asurface.

Preferably, the cyclodextrins used in the present invention are highlywater-soluble such as, alpha-cyciodextrin and/or derivatives thereof,gamma-cyclodextrin and/or derivatives thereof, derivatisedbeta-cyclodextrins, and/or mixtures thereof. The derivatives ofcyclodextrin consist mainly of molecules wherein some of the OH groupsare converted to OR groups. Cyclodextrin derivatives include, e.g.,those with short chain alkyl groups such as methylated cyclodextrins,and ethylated cyclodextrins, wherein R is a methyl or an ethyl group;those with hydroxyalkyl substituted groups, such as hydroxypropylcyclodextrins and/or hydroxyethyl cyclodextrins, wherein R is a—CH2-CH(OH)—CH3 or a —CH2CH2-OH group; branched cyclodextrins such asmaltose-bonded cyclodextrins; cationic cyclodextrins such as thosecontaining 2-hydroxy-3-(dimethylamino)propyl ether, wherein R isCH2-CH(OH)—CH2-N(CH3)2 which is cationic at low pH; quaternary ammonium,e.g., 2-hydroxy-3-(trimethylammonio)propyl ether chloride groups,wherein R is CH2-CH(OH)—CH2-N(CH3)3C; anionic cyclodextrins such ascarboxymethyl cyclodextrins, cyclodextrin sulfates, and cyclodextrinsuccinylates; amphoteric cyclodextrins such as carboxymethyl/quaternaryammonium cyclodextrins; cyclodextrins wherein at least one glucopyranoseunit has a 3-6-anhydro-cyclomalto structure, e.g., themono-3-6-anhydrocyclodextrins.

Highly water-soluble cyclodextrins are those having water solubility ofat least about 10 g in 100 ml of water at room temperature, preferablyat least about 20 g in 100 ml of water, more preferably at least about25 g in 100 ml of water at room temperature. The availability ofsolubilized, uncomplexed cyclodextrins is beneficial for effective andefficient odour control performance when used in combination with copper(II) and hydrogen peroxide in the composition of the present invention.Solubilized, water-soluble cyclodextrin can exhibit more efficient odourcontrol performance than non-water-soluble cyclodextrin when depositedonto surfaces.

Examples of preferred water-soluble cyclodextrin derivatives suitablefor use herein are hydroxypropyl alpha-cyclodextrin, methylatedalpha-cyclodextrin, methylated beta-cyclodextrin, hydroxyethylbeta-cyclodextrin, and hydroxypropyl beta-cyclodextrin. Hydroxyalkylcyclodextrin derivatives preferably have a degree of substitution offrom about 1 to about 14, more preferably from about 1.5 to about 7,wherein the total number of OR groups per cyclodextrin is defined as thedegree of substitution. Methylated cyclodextrin derivatives typicallyhave a degree of substitution of from about 1 to about 18, preferablyfrom about 3 to about 16. A known methylated beta-cyclodextrin isheptakis-2,6-di-O-methyl-[beta]-cyclodextrin, commonly known as DIMEB,in which each glucose unit has about 2 methyl groups with a degree ofsubstitution of about 14. A preferred, more commercially available,methylated beta-cyclodextrin is a randomly methylated beta-cyclodextrin,commonly known as RAMEB, having different degrees of substitution,normally of about 12.6.

It is also preferable to use a mixture of cyclodextrins. Such mixturesabsorb odours more broadly by complexing with a wider range ofodoriferous molecules having a wider range of molecular sizes.Preferably at least a portion of the cyclodextrins is alpha-cyclodextrinand its derivatives thereof, gamma-cyclodextrin and its derivativesthereof, and/or derivatised beta-cyclodextrin, more preferably a mixtureof alpha-cyclodextrin, or an alpha-cyclodextrin derivative, andderivatised beta-cyclodextrin, even more preferably a mixture ofderivatised alpha-cyclodextrin and derivatised beta-cyclodextrin, mostpreferably a mixture of hydroxypropyl alpha-cyclodextrin andhydroxypropyl beta-cyclodextrin, and/or a mixture of methylatedalpha-cyclodextrin and methylated beta-cyclodextrin.

The composition of the present invention can also be used in an articleof manufacture comprising said composition plus a spray dispenser. Whenthe commercial embodiment of the article of manufacture is used, it isoptional, but preferable, to include the preservative. Therefore, themost basic article of manufacture comprises a composition according tothe present invention and a dispenser, which may be a liquid dispenser,a spray dispenser or a foam dispenser. The article of manufacture hereinmay comprise any suitable liquid, spray or foam dispenser. Morepreferably, the spray dispenser is a non-aerosol, manually activated ormechanically pumped, pump-spray dispenser. Said pump-spray dispenser mycomprise a container and a pump mechanism which securely screws or snapsonto the container. The container comprises a vessel for containing thecomposition to be dispensed.

In a further embodiment the present invention provides a method ofmalodour control, which method comprises deploying a malodour removingreducing or suppressing composition according to the present inventionto a source of malodour in the form of a liquid, a foam or an aerosol.Preferably the composition is deployed as an aerosol. Thus thecomposition of the present invention may be used by distributing, e.g.,by placing the aqueous solution into a dispensing means, preferably aspray dispenser and spraying an effective amount onto the desiredsurface or article. An effective amount as defined herein means anamount sufficient to remove, reduce or suppress odour to the point thatit is not discernible by the human sense of smell. In a preferredembodiment the composition is delivered to the malodourous atmosphere asan aerosol through a rotary atomizer system.

Thus the present invention relates to the method of spraying a mist oraerosol of an effective amount of composition into the air to remove,reduce or suppress malodour. application as an aerosol through a rotaryatomizer systems

The present invention also provides a odour malodour removing reducingor suppressing kit comprising a stabilized hydrogen peroxide compositionas described herein and a separate copper (II) solution. In this formthe kit may be supplied to end users and the two compositions may bemixed in appropriate proportions just prior to utilization for theremoving reducing or suppressing of malodour. The kit will have a longershelf life than the combined solutions and in kit form there is moreflexibility for the end user to alter the proportions of copper tohydrogen peroxide in the final composition for any given malodourremoving reducing or suppressing scenario. Formulation flexibility isfurther achieved by dilution of both or either of the kit parts withwater before use.

The invention is further illustrated and will be further understood withreference to the following examples.

EXAMPLE 1

A copper containing composition was prepared as follows: 20 L ofmonopropylene glycol was added to a first container equipped with amixer containing 24 L of non-ionic surfactant (SURFAC UN65/95, which isa C9-11 alcohol with 6.5 moles ethylene oxide, 95% active in 5% water,as supplied by Surfachem Group Ltd, 100 Wellington Street, Leeds, WestYorkshire, LS1 4LT, United Kingdom), with stirring. 30 L of hydrogenperoxide (35% in water) was added to the container with mixing for 20minutes. This mixture is a stabilized hydrogen peroxide solution. Asecond container was charged with 300 L of water and the contents of thefirst container were pumped into the second container. 0.763 Kg ofhydrated copper sulphate (CuSO₄.5H₂O) was added to the first containerand dissolved in 50 L of water, with stirring for 10 mins after whichthe copper sulphate solution was pumped from the first container to thesecond container with stirring. The volume of the composition in thesecond tank was adjusted to 700 L with water.

As transfer of the copper sulphate solution was near completion a browncolour developed within the composition in the second container and thispersisted for at least 10 hours. The composition in the second containeralso gave off a gas (oxygen) and the brown colour began to fade afterabout 4 hours. The solution was allowed to stand for over 48 hours andthe remaining brown solution was stable indefinitely. The pH of thefinal composition was 4.5. Although this composition was relativelyunstable the composition as produced and diluted was effective inremoving and/or suppressing malodours.

EXAMPLE 2

A copper containing composition was prepared as follows: 20 L ofmonopropylene glycol was added to a first container equipped with amixer containing 24 L of nonionic surfactant (SURFAC UN65/95, which is aC9-11 alcohol with 6.5 moles ethylene oxide, 95% active in 5% water, assupplied by Surfachem Group Ltd, 100 Wellington Street, Leeds, WestYorkshire, LS1 4LT, United Kingdom), with stirring. 30 L of hydrogenperoxide (35% in water) was added to the container with mixing for 20minutes. A second container was charged with 300 L of water and thecontents of the first container were pumped into the second container.0.763 Kg of hydrated copper sulphate (CuSO₄.5H₂O) was added to the firstcontainer and dissolved in 50 L of water, with stirring for 10 minsafter which the copper sulphate solution was pumped from the firstcontainer to the second container with stirring. The volume of thecomposition in the second tank was adjusted to 700 L with water. Astransfer of the copper sulphate solution was near completion a browncolour developed within the composition in the second container.

After addition of the copper sulphate solution was completed 2.002 Kg ofcitric acid was added to the second container composition in 250 gportions with stirring. On completion of the addition of citric acid thebrown colour disappeared and the final composition was a blue colourtypical of copper (II) solutions. The pH of the final composition wasmeasured at 2.5. The final composition was stable and did not produceoff gases. Although not wishing to be bound by theory it is believedthat the citric acid buffered the composition and stabilized the copperperoxide complex formed during manufacture of the composition. Thecomposition was found to be particularly active in removing malodours.

EXAMPLE 3

100 ml aliquots of the brown suspension/solution as prepared accordingto Example 1 were treated with appropriate amounts of solid citric acidand the time taken for the brown discoloration to disappear and for thecomposition to turn pure blue was determined and recorded.

1. 100 ml brown solution=1 g of citric acid crystals took 10 minutes

2. 100 ml brown solution=2 g of citric acid crystals took 7 minutes

3. 100 ml brown solution=8 g of citric acid crystals took 5 minutes.

For the large scale preparation of the composition citric acid should beused to lower the pH and to speed up the rate of reaction convertingbrown copper peroxide to a pure blue solution. The pure blue solution ismore stable and superior for odour control than the brownsuspension/solution.

EXAMPLE 4

A copper free composition was prepared as follows: 0.6 L of non-ionicsurfactant (Surfac UN65/95) and 0.5 L of monoproplyeneglycol were mixedtogether in a large beaker. To this mixtures was added 0.75 L ofhydrogen peroxide (35% hydrogen peroxide) with stirring, which resultedin a temperature rise of about 10° C. To this mixtures was added 3.150 Lof distilled water with make up to a final composition volume of ˜5 L.

EXAMPLE 5

Sample of liquid/solid waste from an abattoir was available and was usedas a control; 4 ml of the sample of foul smelling suspension was placedon clean paper towels. The compositions of Example 2 and Example 4 wereintroduced to a spraying apparatus and one spray of each composition wasapplied to the foul smelling samples on the paper towels. Sixindividuals were then asked to assess the residual odour. All sixindividuals (3 female and 3 male) selected the copper-containingformulation as giving the least residual odour. This indicates that thecomposition containing copper is much better at controlling odour thanthe copper-free composition.

EXAMPLE 6

Six solutions were prepared using fixed weights of copper(II) sulphatewith variable weights (concentrations) of hydrogen peroxide solution.The fixed weight of copper sulphate was 2.5 g dissolved in 25 mldistilled water and the varying hydrogen peroxide concentrations wereprepared as follows:—

Sample Cu:H₂O₂ Vol 35% H₂O₂ + No (molar ratios) Vol H₂O Vol % H₂O₂ 11:100 90 ml + 10 ml 25.2 2 1:50  44 ml + 56 ml 12.32 3 1:25  22 ml + 78ml 6.16 4 1:20  18 ml + 82 ml 5.04 5 1:10   9 ml + 91 ml 2.52 6 1:5  4.5 ml + 95.5 ml 1.26

These hydrogen peroxide solutions were all made up to 100 ml and thetotal volume of copper solution plus peroxide solution was 125 ml. Thecopper sulphate solutions were added to the appropriate peroxidesolutions with stirring.

During preparation and mixing none of these six solutions produced abrown colour; the only colour was that of the copper sulphate. Thisconfirms that the brown discoloration was not produced as a result ofthe combination of these components.

To each solution was added 5 ml of monopropylene glycol and no colourchange was observed. To each solution was added 5 ml of nonionicsurfactant (Surfac 65/95) and there was an immediate generation of abrown/green colour. Solutions 1-4 gave the most intense colour and 5 and6 the least colour. These colour persisted for at least 4 hours at roomtemperature.

Although the mechanism is not understood it is clear that at theprevailing pH of these compositions the surfactant has a role in thegeneration of the brown colour formation with copper and hydrogenperoxide. The reasons for this are unclear at present. The brown colourdecreased with decreasing hydrogen peroxide concentration indicatingthat the formation of this brown/green colour is also related to therelevant surfactant and hydrogen peroxide concentrations.

EXAMPLE 7

Separate solutions were prepared of surfactant and hydrogen peroxide.

Surfactant solution: 4.5 ml Surfac+45.5 ml water=50 ml pH=5Hydrogen peroxide Solution: 1.94 ml (35%) peroxide+48 ml water=50 mlpH=5These solutions were mixed together to give 100 ml of solution with anapproximate molar ratio of 1 Surfac:2 peroxide.0.86 g of copper sulphate pentahydrate was added to the combinedsolution. The solution became green and pH dropped to 4.This experiment was repeated with a 20 fold increase in the amount ofhydrogen peroxide used.4.5 ml Surfac+45.5 ml water=50 ml20 ml peroxide+30 ml water=50 ml pH=3The same mass of copper sulphate was added and this time there was nochange in colour and the solution remained pure blue. Thus there was nocolour change and no formation of other copper compounds with thisexcess amount of peroxide.

EXAMPLE 8

0.4 L of nonionic surfactant (SURFAC 65/95) was mixed with 1.2 Lo waterin a 5 L plastic container and no excess foaming was observed at thisstage. To this mixture was added 0.2 L of 35% hydrogen peroxide withcareful mixing and a little more foaming occurred at this stage. To thismixture was added 0.04 L of monopropylene glycol with mixing. There wassome foaming and what appeared to be a cloudiness appeared on thesurface of the formulation. After ˜⅔ hours the surface cloudiness wasmuch less and the quantity of foaming had reduced.

This copper free composition was compared against a commercial odoursuppressing product called Tego Sorb® (Evonik Industries). Thecomparison indicated that there was little difference between the two interms of odour suppression.

A further experiment using copper sulphate mixed into the composition ina slightly diluted formula, still had poor odour-reducing properties.This result indicated that the order of addition of the components inthe manufacture of the composition of the present invention is criticalto achieve an active composition. In this example the hydrogen peroxidewas added to an aqueous mixture of surfactant followed by themonopropylene glycol. Foaming was observed and cloudiness suggestingdecomposition of the hydrogen peroxide addition of the copper sulphateto this composition did not result in the formation of the active copperhydrogen peroxide component observed in Example 1 or 2.

EXAMPLE 9

The following composition was prepared.

ml vol % SURFAC  600 12 MPG  500 10 H₂O₂ (35%)  143 10 H₂O 3687 ~49 4930CuSO₄5H₂O 4 g in 70 ml

The monopropylene glycol (MPG) was added to the nonionic surfactant(SURFAC) with stirring and easily mixed and dissolved. Then the hydrogenperoxide was carefully added to this mixture and again easily mixed intothe solution. At this stage the pH was pH=5. To this mixtures was addedthe distilled water and finally the copper sulphate as solutiondissolved in 70 ml of water was added. No precipitate or discolorationwas apparent and a pale blue solution formed with no gassing. Thisexperiment was repeated but this time with the addition of 19 g ofhydrated copper sulphate in solution in 70 ml water. Immediate brownprecipitate was formed which dissolved and the solution went pure blueafter the addition of 20 g of citric acid. pH at the end of theexperiment was 2-3.

The high level of copper compared to hydrogen peroxide is believed tohave resulted in the formation of the undesirable brown precipitate,which is then taken onto solution in this copper sulphate system byaddition of citric acid.

EXAMPLE 10

A composition as indicated below was prepared in order to providenonionic surfactant:monopropylene glycol:hydrogen peroxide in the moleratios of 2:6:6, which for a 2% hydrogen peroxide solution reduces tothe following percentage composition excluding copper sulphate andcitric acid:—

% ml Surfac 8   80 MPG  4.6  46 H₂O₂ 2  57 (35%) Water 85.4  817 100  1000

The composition was prepared as follows: A premixed of Surfac (160 ml),MPG (92 ml), hydrogen peroxide (114 ml of 35% solution) and water (1634ml) was prepared as in Example 9. To this premix was then added citricacid solution (5.7 g in ˜20 ml water) and finally pure copper sulphate(2 g in ˜50 ml). During mixing there were no problems with excessivefoaming or precipitation of brown copper peroxide.

EXAMPLE 11

To 400 ml of Surfac was added 230 ml of MPG. Hydrogen peroxide (35%) 285ml was added and ˜3 litres of water added. 25 g of citric acid in 75 mlof water and 12.5 g of copper sulphate hydrate dissolved in 100 ml waterwere added. The rest of the water (up to 5 litres) was added. The pureblue solution was stable and did not produce oxygen on standing.

EXAMPLE 12

Surfac (50 ml) plus MPG (29 ml) plus 35% hydrogen peroxide (57 ml). Allmixed together as per usual. Weighed out 3.4 g copper citrate and triedto dissolve it in citric acid solution but would not dissolve. Added 10g of sodium citrate in 50 ml water and added to the bulk formulation andthe pale green/blue solution formed with pH=6.

Tested using stink bomb as a source of H₂S and ammonia. Broke stink bombin enclosed room of approximately 15 m3. Left for one minute. Sprayedsolution into headspace and closed the door. Left for one minute to act.Opened door and level of odour was detected subjectively. The solutionappeared to have significantly reduced the level of odour, especiallythe ammonia.

EXAMPLE 13

A similar composition to previous examples was prepared using areplacement surfactant. The surfactant used was lmbentin-AGS/55, a lowodour non-ionic surfactant (a liquid C₁₁-C₁₅ alcohol with 9 EO's) assupplied by Kolb-Switzerland. The formulation for the premix was asfollows:—

vol % ml Imbentin 5  50 MPG 3  30 H₂O₂ (35%) 1.5  43 Water 89  862Copper solution 1.5  15 1000

For a concentration of 350 ppm copper ion from copper citrate, 1.05 g ofpure copper citrate was helped to dissolve using sodium citrate inapprox 15 ml water to give a pure blue aqua/water colour.

The mixing was OK with virtually no degassing and no separation intolayers. The formulation was tested neat and at a 5:1 dilution withhydrogen sulphide and ammonia from “stink bombs”. The test was carriedout in a confined space (small room) and both the neat and 50% dilutedcompositions were effective against hydrogen sulphide and ammonia whenthe container and surrounding air were sprayed with the composition. Thetest was repeated with the leachate and again both products wereeffective, the neat formulation being a little better than the 5:1dilution.

EXAMPLE 14

A similar composition to previous examples was prepared using areplacement surfactant. This surfactant Surfac 90/90 was supplied bySurfachem Group Ltd, 100 Wellington Street, Leeds, West Yorkshire, LS14LT, United Kingdom and was a C₉-C₁₁ alcohol ethoxylate with 9 ethyleneoxide groups. This surfactant was used along to make one formulationhaving 500 ppm Cu²⁺ from copper sulphate and a further formulationhaving 500 ppm Cu²⁺ from copper citrate. Testing with foul smellingabattoir liquid on for most of a day showed that the citrate derivedformulation was superior to the sulphate derived formulation.

EXAMPLE 15

Various formulations were prepared incorporating beta-cyclodextrin.

Stabilized Hydrogen Peroxide Composition

vol % ml Surfactant  5  50 MPG  3  30 H₂O₂ (35%)  1.5  43 Water  90.5 877 100   1000

The cyclodextrin used was CAVASOL® W7 HP as supplied by Wacker ChemieAG, Burghausen, Germany. This product is a hydroxypropylbeta-cyclodextrin. To achieve a cyclodextrin concentration of 0.09 wt %,0.9 g (900 ppm) per L of CAVASOL was added to stabilized hydrogenperoxide composition. To achieve a soluble copper level of 350 ppm Cu²⁺1.05 g per L of copper citrate was added to the stabilized hydrogenperoxide composition. To aid dissolution of the copper citrate anadditional equivalent amount of sodium citrate was used, the solutionbeing made up in 20 ml of hot water with constant stirring.

For testing purposes the following compositions at a volume of 1 L wereprepared:

1. Stabilized hydrogen peroxide composition with copper andcyclodextrin.

2. Stabilized hydrogen peroxide composition with copper but withoutcyclodextrin

3. Stabilized hydrogen peroxide composition without copper but withcyclodextrin

The solutions were stable after cyclodextrin addition. Two types ofodour tests were carried out using commercial ‘stink bombs’ in aconfined space and foul-smelling abattoir liquor on paper towels.

These tests established qualitatively that the combination of copperion/hydrogen peroxide with cyclodextrin when used in the neat undilutedform outperformed 50/50 diluted formulations in both experiments. Indeedin the foul-liquor tests the copper/hydrogen peroxide cyclodextrinsystem immediately eliminated all foul odours coming from theliquor-soaked paper towel. This shows that the combination ofcopper/hydrogen peroxide with cyclodextrin is particularly beneficialfor the reduction of odour from very severe odour sources.

EXAMPLE 17—EXPERIMENTS WITH DRAEGER® TUBES FOR HYDROGEN SULPHIDE ANDAMMONIA

Using commercial ‘stink bombs’ as a source of hydrogen sulphide andammonia experiments were carried out to determine reductions in levelsof these two gases using the composition of the present invention astypically prepared according to Example 15 without the addition ofcyclodextrin.

Apparatus

Clean 25 L plastic drums were used as the ‘container’ for theexperiments. These were adapted to enable the headspace propertieswithin the containers to be measured using Draeger® Tubes. A thinpolythene film used as a closure to the container to contain the gasesduring the tests. Stink bombs were broken into the plastic drum, whichwas immediately sealed and 90 seconds was allowed for the odour todevelop. The levels of gasses were measured with the Draeger® Tubes andafter introduction by spraying of the composition of the presentinvention neat, at 50% dilution and 25% dilution.

Results (all Readings in ppm)

Composition NH₃ (ppm) H₂S (ppm) Neat CONTROL >100 220 With Composition23 5 Reduction (%) >77 98 50% dilution CONTROL >100 250 With Composition30 48 Reduction (%) >70 81 25% dilution CONTROL >100 150 WithComposition 70 40 Reduction (%) >30 73

The data obtained for ammonia and hydrogen sulphide indicatedsignificant reductions in levels of these gases had occurred in thepresence of the composition of the invention at all dilutions. As thedilutions progressed from neat to 50% to 25% there was a stepwisereduction in percentage reductions in both cases.

Tests for Dimethyl Sulphide and Methyl Mercaptan

Similar procedure as before but this time a 5 L capped plastic containerwas used. 12 ml of leachate was placed in the container, 90 seconds wereallowed to pass and the readings taken for both methyl mercaptan anddimethyl sulphide. 12 ml of neat composition of the invention was addedto the container, 90 seconds was allowed to pass to allow the odour todevelop and the gas in the container was retested.

Results

There was no evidence for the presence of methyl mercaptan in theleachate. However in the case of the dimethyl sulphide, 3 ppm waspresent before treatment and after treatment with the composition therewas a zero reading for this compound.

Further Tests Using Draeger® Tubes with Methyl Mercaptan

A new experimental procedure was devised so that the foul-smellingadditive, methyl/ethyl mercaptans in commercial propane gas was used asa controlled source of mercaptans. The presence of the inert hydrocarbongases, methane, propane butane are believed to have no deleteriouseffect on the tests

A 5 litre plastic container was filled with propane gas from a cylinderby downward displacement of water and the sample then tested forCH₃/C₂H₅SH with appropriate Draeger® Tubes, which had a 0.5-5 ppmmercaptan range. The container was sealed with a plastic cover with an 8mm hole drilled through the lid. The gas seal being achieved usingpolythene film.

The test procedure was carried out in duplicate, the control level ofmercaptans was >5 ppm (possibly <10 ppm).

After vigorously shaking with near composition according to the presentinvention for 1 minute, the gas was again sampled for mercaptans withDraeger® Tubes. It was found that the residual level of mercaptans wasbetween 0 and 0.5 ppm.

This experiment was repeated using a commercial residential odourtreatment product called Febreze® manufactured and sold by Proctor &Gamble.

With neat Febreze® the tests showed that the level of mercaptansremained unchanged with more than 5 ppm of mercaptan present aftertreatment in the container after 1 minute of mixing.

1. An aqueous composition comprising: a) at least one source of copper,b) hydrogen peroxide or a source of hydrogen peroxide, c) one or morealcohols, and d) one or more surfactants.
 2. A method of malodourcontrol, which method comprises deploying an aqueous compositionaccording to claim 1 to the source of malodour.
 3. A method of malodourcontrol, which method comprises deploying an aqueous compositionaccording to claim 1 to a malodour containing environment as an aerosol.4. An stabilized aqueous hydrogen peroxide composition comprising: a)hydrogen peroxide or a source of hydrogen peroxide, b) one or morealcohols, and c) one or more surfactants.
 5. A method for themanufacture of an aqueous composition, which method comprises: a)preparing an aqueous solution comprising at least one alcohol, at leastone surfactant and hydrogen peroxide, and b) adding a source of copper(II) solution to the solution prepared in (a).
 6. A method according toclaim 5 wherein the solution provided at step (a) is a stabilizedaqueous hydrogen peroxide composition comprising: a) hydrogen peroxideor a source of hydrogen peroxide, b) one or more alcohols, and c) one ormore surfactants.
 7. A method according to claim 5 wherein in step (a)the alcohol is added to the surfactant before addition of water withcareful mixing.
 8. A method according to claim 5 wherein the hydrogenperoxide is added to an alcohol/surfactant mixture before the additionof water with careful stirring.
 9. A method according to claim 5 whereinwater is added to the mixture of alcohol, surfactant and hydrogenperoxide with mixing.
 10. A method according to claim 5 wherein theaqueous copper (II) solution comprises one or more of copper (II)sulfate, copper (II) chloride, copper (II) nitrate or copper (II)citrate.
 11. A method according to claim 5 wherein the aqueous copper(II) solution comprises copper (II) citrate.
 12. A method according toclaim 5 wherein the aqueous copper (II) solution further comprises asodium or potassium salt.
 13. A method as claimed in claim 5 whereincitric acid is added to the combination of solution (a) and/or solution(b) or the combination of solutions (a) and (b).
 14. A composition asclaimed in claim 1 comprising 1 to 20% by weight of hydrogen peroxide.15. A composition or method as claimed in claim 1 wherein the surfactantis a non-ionic surfactant.
 16. A composition according to claim 15wherein the non-ionic surfactant is an alcohol ethoxylate of thefollowing general structure (I):R—(OCH₂CH₂)_(n)—OH   (I) wherein R is an alkyl group of the parentalcohol and n=number of molecules of ethylene oxide present.
 17. Acomposition according to claim 16 wherein R is a hydrocarbon grouphaving from 8 to 22 carbon atoms (C₈, to C₂₂ alkyl group), preferablythe surfactant has a hydrocarbon group R having from 8 to 15 carbonatoms and more preferably 9 to 11 carbon atoms.
 18. A compositionaccording to claim 16 wherein n is from 3 to 40, more preferably from 3to 30, more preferably from 3 to 20, more preferably from 5 to 10 andmost preferably from 5 to
 8. 19. A composition according to claim 1,wherein the alcohol is a diol.
 20. A composition according to claim 19wherein the diol is one or more low molecular weight diols having from 3to 10 carbon atoms in the alkyl moiety.
 21. A composition according toclaim 20 wherein the diol is a vicinal diol.
 22. A composition accordingto claim 21 wherein the diol is propane-1,2-diol (monopropylene glycol).23. A composition according to claim 1 wherein the concentration ofhydrogen peroxide in the final composition is 3% or less by weight. 24.A composition according to claim 1 wherein the concentration of hydrogenperoxide is 2% or less by weight.
 25. A composition according to claim 1wherein the concentration of hydrogen peroxide is 1% or less by weight.26. A composition according to claim 1 wherein the concentration ofhydrogen peroxide is 0.5% or less, preferably 0.2% or less and mostpreferably 0.1% or less by weight.
 27. A composition according to claim1 wherein the concentration of hydrogen peroxide is 100 ppm or less andthe concentration of copper is 10 ppm or less.
 28. A malodour treatmentkit comprising a composition according to claim 4 and an aqueouscomposition comprising a source of copper.